Belén Ferrer

Bio: Belén Ferrer is an academic researcher from Polytechnic University of Valencia. The author has contributed to research in topics: Flash photolysis & Metal-organic framework. The author has an hindex of 18, co-authored 49 publications receiving 1496 citations. Previous affiliations of Belén Ferrer include University of Bologna.

Semiconductor Behavior of a Metal-Organic Framework (MOF)

Abstract: Upon light excitation MOF-5 behaves as a semiconductor and undergoes charge separation (electrons and holes) decaying in the microsecond time scale. The actual conduction band energy value was estimated to be 0.2 V versus NHE with a band gap of 3.4 eV. Photoinduced electron transfer processes to viologen generates the corresponding viologen radical cation, while holes of MOF-5 oxidizes N,N,N',N'-tetramethyl-p-phenylenediamine. One application investigated for MOF-5 as a semiconductor has been the shape-selective photocatalyzed degradation of phenol in aqueous solutions.

Ti as Mediator in the Photoinduced Electron Transfer of Mixed-Metal NH2–UiO-66(Zr/Ti): Transient Absorption Spectroscopy Study and Application in Photovoltaic Cell

Abstract: A series of mixed-metal NH2–UiO-66(Zr/Ti) with different percentages of exchanged Ti have been prepared and studied by transient absorption spectroscopy (TAS). The photogenerated transients from mixed NH2–UiO-66(Zr/Ti) exhibit at short time scales two defined absorption bands, evolving to a continuous absorption band expanding from 300 to 700 nm at longer time scales. The observed spectral changes are compatible with an initial formation of Ti3+–O–Zr4+ and its further transformation to Ti4+–O–Zr3+ via metal–metal electron exchange, thus providing support to the role of substituted Ti as mediator to facilitate electron transfer from excited ligand to the (Zr/Ti)6O4(OH)4 nodes in mixed NH2–UiO-66(Zr/Ti). The slow recombination of photogenerated electrons and holes in the mixed NH2–UiO-66(Zr/Ti) has been advantageously used for the construction of a photovoltaic cell fabricated with the mixed NH2–UiO-66(Zr/Ti), reaching a higher photon-to-current efficiency than NH2–UiO-66(Zr).

Visible-light photocatalytic activity of gold nanoparticles supported on template-synthesized mesoporous titania for the decontamination of the chemical warfare agent Soman

Abstract: Mesoporous titania containing gold nanoparticles has been found to be an efficient photocatalyst for the visible-light decontamination of Soman. This contrasts with the complete lack of visible-light activity of analogous mesoporous titania sample without containing Au and is attributed to light absorption by the gold nanoparticles surface plasmon band. The possibility that Soman degradation occurs by light-induced heating is unlikely since no variation of the temperature is observed in the irradiation. The solid photocatalysts have been prepared in a single step in which incorporation of gold and formation of titania occur in the same sol–gel process. It was observed that the molar proportion of Pluronic added to the synthesis sol as template to produce mesoporosity in the material plays an important role controlling the textural properties, surface area and pore diameter, intensity of the surface plasmon band and gold loading of the solid photocatalysts. The visible-light photocatalytic activity of mesoporous titania containing gold nanoparticles towards deadly Soman is remarkable and it constitutes an environmentally friendly system operating under ambient light at the green atmosphere without the need of corrosive or toxic chemicals.

Enhancing visible-light photocatalytic activity for overall water splitting in UiO-66 by controlling metal node composition

Abstract: Financial support by the Spanish Ministry of Science and Innovation (Severo Ochoa and RTI2018-098237-CO21) and Generalitat Valenciana (Prometeo 2017/083) is gratefully acknowledged. S.N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016), Ministerio de Ciencia, Innovacion y Universidades RTI2018-099482-A-I00 project and Generalitat Valenciana grupos de investigacion consolidables 2019 (ref: AICO/2019/214) project.

Photochemical Response of Commercial MOFs: Al2(BDC)3 and Its Use As Active Material in Photovoltaic Devices

Abstract: The presence of organic linkers in MOFs allows introducing response in the solid upon chemical, electrochemical, or photochemical excitation of these units. In the present study, we report the intrinsic photoresponse of four commercially available MOFs as well as after incorporation of some organic guests. Laser flash photolysis measurements have allowed us to detect transient species upon irradiation of commercial Al2(BDC)3. The signal has been rationalized as derived from the photochemical generation of charge separated states. In contrast to Al2(BDC)3, the other three commercial MOFs tested did not exhibit any signal. The photoinduced charge separation in Al2(BDC)3 can be modulated by inclusion of organic guests that can act as traps of electrons or holes increasing the lifetime of charge separation. When the oxidation potential of the organic guest is low, as in the case of 1,4-phenylendiamine, PDA, we have been able to observe spontaneous charge separation even for Fe-BTC and Cu3(BTC)2. The basic und...

Selective gas adsorption and separation in metal–organic frameworks

Abstract: Adsorptive separation is very important in industry. Generally, the process uses porous solid materials such as zeolites, activated carbons, or silica gels as adsorbents. With an ever increasing need for a more efficient, energy-saving, and environmentally benign procedure for gas separation, adsorbents with tailored structures and tunable surface properties must be found. Metal–organic frameworks (MOFs), constructed by metal-containing nodes connected by organic bridges, are such a new type of porous materials. They are promising candidates as adsorbents for gas separations due to their large surface areas, adjustable pore sizes and controllable properties, as well as acceptable thermal stability. This critical review starts with a brief introduction to gas separation and purification based on selective adsorption, followed by a review of gas selective adsorption in rigid and flexible MOFs. Based on possible mechanisms, selective adsorptions observed in MOFs are classified, and primary relationships between adsorption properties and framework features are analyzed. As a specific example of tailor-made MOFs, mesh-adjustable molecular sieves are emphasized and the underlying working mechanism elucidated. In addition to the experimental aspect, theoretical investigations from adsorption equilibrium to diffusion dynamics via molecular simulations are also briefly reviewed. Furthermore, gas separations in MOFs, including the molecular sieving effect, kinetic separation, the quantum sieving effect for H2/D2 separation, and MOF-based membranes are also summarized (227 references).

Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis

Abstract: A fundamental aim in the field of catalysis is the development of new modes of small molecule activation. One approach toward the catalytic activation of organic molecules that has received much attention recently is visible light photoredox catalysis. In a general sense, this approach relies on the ability of metal complexes and organic dyes to engage in single-electron-transfer (SET) processes with organic substrates upon photoexcitation with visible light. Many of the most commonly employed visible light photocatalysts are polypyridyl complexes of ruthenium and iridium, and are typified by the complex tris(2,2′-bipyridine) ruthenium(II), or Ru(bpy)32+ (Figure 1). These complexes absorb light in the visible region of the electromagnetic spectrum to give stable, long-lived photoexcited states.1,2 The lifetime of the excited species is sufficiently long (1100 ns for Ru(bpy)32+) that it may engage in bimolecular electron-transfer reactions in competition with deactivation pathways.3 Although these species are poor single-electron oxidants and reductants in the ground state, excitation of an electron affords excited states that are very potent single-electron-transfer reagents. Importantly, the conversion of these bench stable, benign catalysts to redox-active species upon irradiation with simple household lightbulbs represents a remarkably chemoselective trigger to induce unique and valuable catalytic processes. Open in a separate window Figure 1 Ruthenium polypyridyl complexes: versatile visible light photocatalysts.

Understanding TiO2 photocatalysis: mechanisms and materials.

Abstract: Jenny Schneider,*,† Masaya Matsuoka,‡ Masato Takeuchi,‡ Jinlong Zhang, Yu Horiuchi,‡ Masakazu Anpo,‡ and Detlef W. Bahnemann*,† †Institut fur Technische Chemie, Leibniz Universitaẗ Hannover, Callinstrasse 3, D-30167 Hannover, Germany ‡Faculty of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan Key Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, China

Engineering Metal Organic Frameworks for Heterogeneous Catalysis

Abstract: 2.2. MOFs with Metal Active Sites 4614 2.2.1. Early Studies 4614 2.2.2. Hydrogenation Reactions 4618 2.2.3. Oxidation of Organic Substrates 4620 2.2.4. CO Oxidation to CO2 4626 2.2.5. Phototocatalysis by MOFs 4627 2.2.6. Carbonyl Cyanosilylation 4630 2.2.7. Hydrodesulfurization 4631 2.2.8. Other Reactions 4632 2.3. MOFs with Reactive Functional Groups 4634 2.4. MOFs as Host Matrices or Nanometric Reaction Cavities 4636

Applications of metal–organic frameworks in heterogeneous supramolecular catalysis

Abstract: This review summarizes the use of metal–organic frameworks (MOFs) as a versatile supramolecular platform to develop heterogeneous catalysts for a variety of organic reactions, especially for liquid-phase reactions. Following a background introduction about catalytic relevance to various metal–organic materials, crystal engineering of MOFs, characterization and evaluation methods of MOF catalysis, we categorize catalytic MOFs based on the types of active sites, including coordinatively unsaturated metal sites (CUMs), metalloligands, functional organic sites (FOS), as well as metal nanoparticles (MNPs) embedded in the cavities. Throughout the review, we emphasize the incidental or deliberate formation of active sites, the stability, heterogeneity and shape/size selectivity for MOF catalysis. Finally, we briefly introduce their relevance into photo- and biomimetic catalysis, and compare MOFs with other typical porous solids such as zeolites and mesoporous silica with regard to their different attributes, and provide our view on future trends and developments in MOF-based catalysis.